Philipp von Mansfeld (1589 - 8 April 1657), was Graf von (Count of) Mansfeld, Vorderort and Bornstedt who commanded troops during the Thirty Years' War. He first fought on the side of the Swedish Empire under his second-cousin, was captured, changed allegiance and raised a navy for General Albrecht von Wallenstein. Later, he commanded troops as Feldmarschall of the Holy Roman Empire.
Mansfeld was born in 1589, the son of Bruno, Count of Mansfeld-Vorderort and his wife, Christine of Barby and Mühlingen.
In 1611 Mansfeld married Maria von Mansfeld-Hinterort and they had six children:
Upon her death, Mansfeld married, in 1630, Margaretha Catharine von Lobkowicz but had no further children.
Mansfeld first served under Ernst von Mansfeld and the Swedish Empire during the Thirty Years' War. The two were, in fact, second-cousins; Mansfeld's grandfather and Ernst von Mansfeld's father were half-brothers. Ernst von Mansfeld had originally fought on the side of the Catholics and Leopold V, Archduke of Austria, but conflicts with the Archduke had driven him to join the side of the Protestants.
In 1622, Ernst von Mansfeld's troops faced the army of Johann Tserclaes, Count of Tilly at the Battle of Mingolsheim. They were victorious but during Tilly's final push, Mansfeld's troops were overwhelmed and he was captured along with a number of other senior officers. Questioned about his relationship to his commanding officer, Mansfeld suggested he was a true Graf von Mansfeld; "ich bin der rechte, vnd der ander nicht" ("I am the true, the other is not") - a reference to his second-cousin's illegitimate birth.